Making the climatic diagnosis of Changjiang Three Gorge Region by the maximum entropyspectrum analysis and wavelet analysis,we discovered that the main periods of the annual andwintertime precipitation variation in the east subregion differ from that in the west subregion.Theformer is a period of about 2 years,and the latter is about 5—6 years.Their wavelet patterns arealso apparently different between two subregions:the alternate positive and negative waveletpatterns for the west,but not so regular for the east.These provide a climatic background for theimplementation of Three Gorge Project.We also found that the historical reason of the mainperiods by combing synthetically spectrum analysis and wavelet analysis could be realized.Inaddition we suggest a gist of the climate forecast by analogy analysis based on the 2-dimensionalwavelet figures. Making the climatic diagnosis of Changjiang Three Gorge Region by the maximum entropyspectrum analysis and wavelet analysis, we discovered that the main periods of the annual and wintertime precipitation variation in the east subregion differ from that in west subregion. Theformer is a period of about 2 years , and the latter is about 5-6 years. Their wavelet patterns arealso apparently different between two subregions: the alternate positive and negative wavelet patterns for the west, but not so regular for the east. these provide a climatic background for the implantation of the Three Gorge Project .We also found that the historical reason of the mainperiods by combing synthetically spectrum analysis and wavelet analysis could be realized. Addition we suggest a gist of the climate forecast by analogy analysis based on the 2-dimensional wavelets figures.